The objective of this research project is to investigate the effects of social evolution on aging and mortality patterns in the honey bee (Apis mellifera L). The study of social influences on aging is largely restricted to investigations on humans that have a necessarily limited experimental approach. Social insect colonies are complex adaptive systems representing one of the major evolutionary transitions. They allow studies of aging at different levels of biological organization including the social unit, the individual, physiological processes, and their interactions. Already a model in a number of biological disciplines, the honey bee thus will constitute an important, social model organism for aging research. The first aim is to investigate social determinants of honey bee lifespan, specifically addressing the following questions: a) What are the relative contributions of individual (genetic) properties and social environment to individual lifespan? b) How do group demographics (group size and age composition) affect individual lifespan? How does brood care (intergenerational transfer) influence lifespan? Each of these questions will be addressed in a series of experiments that involve extensive colony manipulations and demographic surveys, age-specific survival measures of multiple, focal cohorts, and direct measures of resource allocation in individuals and colonies. The data will be analyzed to validate concurrent theoretical advances in conjunction with other collaborators in the program project. The second aim is to determine different components of behavioral senescence in honey bee workers. Honey bee foraging performance declines with age. Deterioration of sensory (olfactory, gustatory, visual responsiveness), and motor (flight and locomotion) systems at advanced ages will be studied. Furthermore, higher-order processes such as cognitive abilities (learning and memory) and recruitment behavior (dance tempo) will be investigated for age effects. Honey bee foragers of different age classes will be subjected to well-established behavioral assays. Potential links between the various measures of behavioral senescence and physiological measurements will be investigated, and the role of senescence for societal organization will be scrutinized.